If steel reinforcement bars (“rebars”) as well as plates or fibres are merged with concrete, the reinforced concrete is generated. Reinforcement provides additional tensile potency to concrete. Reinforced Concrete produces several skyscraper buildings within short span of time.
Reinforced Concrete is applied for various structures types and components which range from beams, slabs, walls, columns, foundations and more.
Two types of methods are generally followed for reinforced concrete design :-
1. Working stress method – This method is based on conditions of service load. But this method is outmode.
2. Strength Design Method – This method is based on conditions at loads higher than service loads when failure is occurred.
Strength Design Method considers two load factors – overload factors and strength reduction factor toward safety purpose. Strength Design Method follows the principles that design strength that includes axial force, shear force, bending moment etc. must be higher than or identical to Factored Load (essential strength).
Design Strength can be calculated with multiplication of nominal strength by strength reduction factor. Nominal strength is measured through static equilibrium and consistency of stress and strain. Factored loads are measured with multiplication of the service load by overload factor U.
Description of Reinforced Concrete Beams: The formal strength of a reinforced concrete beam is figured out if the strain in the extreme compression fibre is identical to the crushing strain of concrete (0.003).
Reinforced concrete beam is categorized as singly reinforced (rebar only in tension region of the section) or doubly reinforced (rebar in tension compression regions of the section).
To gather more knowledge on the strength of reinforced concrete beam, please go through solved example 9-1, example 9-2, example 9-3